The present invention relates to a connector housing having thin-walled portions formed for inspecting short-shots in terminal retaining lances of the connector housing, and a method of manufacturing the same.
FIG. 9 shows an example of a related spacerless connector. A connector housing 40 of this type is formed of a synthetic resin and has therein a plurality of terminal chambers 41 which are juxtaposed horizontally in two upper and lower stages. Insertion ports 42 for inserting terminals 60 are provided in its rear side, while insertion ports 43 into which tab-like electrical contact portions (not shown) of male-type terminals which are mating terminals are inserted are formed in its front side. The terminal chambers 41 are defined by vertical partition walls 44, horizontal partition walls 45, upper and lower wall portions 46 and 47, and left and right wall portions 48 and 49. To be accurate, the terminal chambers 41 on both sides include the left and right wall portions 48 and 49 as constituent elements.
As each terminal 60 is inserted in the respective terminal chamber 41, the terminal 60 upwardly deflects a flexible terminal retaining lance 50 inside the terminal chamber 41. As the terminal 60 is further inserted, the terminal 60 is retained by the terminal retaining lance 50 which has returned resiliently. The terminal 60 is fabricated by bending a thin metal sheet stamped out by press working. A box-shaped electrical contact portion 61 having a spring piece for contact provided therein is formed in a front half of the terminal 60, while a first clamping portion 62a for clamping an insulating coating of an electric wire 65 and a second clamping portion 62b for clamping a core wire are respectively formed with U-shaped cross sections in a rear half of the terminal 60. The terminal in this example is of the so-called female type.
The electrical contact portion 61 formed in a box shape by uprighting side plates 63 from both sides of a bottom plate and by orthogonally bending an extended portion of one side plate 63 toward the other side plate 63 side. Further, a downwardly inclined face 64 is formed on the rear side of the electrical contact portion 61 via a stepped portion. A vertical end face of the stepped portion serves as a portion to be retained corresponding to the terminal retaining lance 50.
The connector housing in this example is not provided with spacers for secondarily retaining the terminals 60. Accordingly, the terminals 60 are not doubly retained, and are retained by the terminal retaining lances 50 alone, so that the connector housing 40 has simple construction.
The connector housing 40 is formed by injecting a molten resin into an unillustrated cavity and allowing the resin to cool and solidify. At this time, the terminal retaining lances 50 of the connector housing 40 are also formed integrally. The connector housing 40 in this example if of the so-called male type.
However, with the above-described connector housing and a method of manufacturing the same, particularly in the case of the connector housings for which there is a demand for downsizing, the vertical partition walls and horizontal partition walls must be set to be thin, and concern has been felt that these partition walls may result in molding defect which is so-called short-shots during injection molding. Particularly in the case of the terminal retaining lances which are projectingly provided in a cantilevered manner from the inner walls, there has been greater concern for the short-shots.
In the case where there has been a short-shot in the terminal retaining lance of the spacerless connector, the terminal can come off, or faulty connection can result, so that the short-shot has been a serious problem. Accordingly, short-shots in the terminal retaining lances are checked by visual inspection or by an image processor.
In view of the above-described aspects, it is an object of the invention to provide a connector housing and a method of manufacturing the same which make it possible to easily and accurately inspect short-shots in the terminal retaining lances at the time of injection molding.
In order to achieve the above object, according to the present invention, there is provided a connector housing, formed with a chamber into which a terminal is inserted, comprising:
a retention member, formed in the chamber so as to retain the inserted terminal therein, the retention member formed by a first portion of a mold which molds the housing; and
an inspection member, formed on an outer face of the housing for inspecting molding defect of the retention member, the inspection member formed by a second portion of the mold having a higher flow resistance than the first portion of the mold.
According to the present invention, there is also provided a connector housing, formed with a chamber into which a terminal is inserted, comprising:
a retention member, formed in the chamber so as to retain the inserted terminal therein; and
an inspection member, formed on an outer face of the housing for inspecting molding defect of the retention member, the inspection member having a thickness dimension thinner than the retention member.
According to the present invention, there is also provided a mold, for molding a connector housing which is formed with a chamber into which a terminal is inserted, a retention member formed in the chamber so as to retain the inserted terminal therein, and an inspection member for inspecting molding defect of the retention member, comprising:
a first portion, having a first flow resistance, for forming the retention member; and
a second portion, having a second low resistance higher than the first flow resistance, for forming the inspection member on an outer face of the housing.
Preferably, the mold further comprises a third portion, from which molten resin for forming the housing is injected. Here, the second portion is furthest from the third portion such that the molten resin is lastly fills the second portion.
According to the present invention, there is also provided a method of manufacturing a connector housing which is formed with a chamber into which a terminal is inserted, a retention member formed in the chamber so as to retain the inserted terminal therein, and an inspection member for inspecting molding defect of the retention member, comprising the steps of:
providing a mold for molding the connector housing;
providing a first portion for forming the retention member in the mold so as to have a first flow resistance member:
providing a second portion for forming the inspection member in the mold at a position where is to be an outer face of the housing, so as to have a second flow resistance higher than the first flow resistance;
injecting molten resin into the mold; and
inspecting an external appearance of the molded inspection member to determine whether molding defect is present on the molded retention member.
Preferably, the second portion providing step includes the steps of, determining a third portion in the mold, from which the molten resin is injected; and determining the second portion as a portion where the molten resin lastly fills.
Here, it is preferable that the second portion is determined by performing a flow analysis of the molten resin within the mold.
In the above configurations, the inspection member is formed in a portion where the molding defect (short-shot) is most likely to occur. Namely, if the external appearance of the inspection member is checked, and a short-shot cannot be detected, it can be estimated that there are no short-shots in the retention member, and that the product can be evaluated as being nondefective. To the contrary, if there is a defect in the external appearance of the inspection member, it can be estimated that there is a defect in the retention member.
The third portion (injection gate) may be plurally provided. In this configuration, the flow of the molten resin is improved.